you dont really need winterboard to install icons.
download 'ifile'. get a bit fimiliar with it.
do a google search for 'jaku'. he's got some pretty wicked icons. what u can do is download the icon pics that you like, go to the applications folder (using ifile) which can be found in /var/mobile/Applications AND /var/stash/Applications.
once you navigate to these folders, look for the application that you want to change the icon for. you will notice a file (in most cases) called
Icon@2x.png with a resolution of either 114x114 or 118x120 (both can be downloaded from jaku website). Simply paste your image file in the respective folder and rename it to the icon file.
Note: i usually back up my stock icon files by adding a "Z" at the end. so my stock icon files are
IconZ@2x.png & my custom image icon is
Icon@2x.png.
hope this helps (atleast for the icons bit)... its not that hard once you get the hang of it by doing 1 or 2 icons.
oh, n dont forget... respring once done.